搜索一个字符，然后计算它出现的次数 Python [关闭]

Question

我是 python 新手，我正在寻找一个程序，要求用户填写一串字符（短语或其他），然后填写特定字符。

程序必须返回字符串中字符出现的次数。我需要使用 .count 函数，但我的代码无法正常工作。

欢迎任何帮助！

def search(text,character):
    '''This function searches for one character, defined as 2nd argument, 
    in a given text / string of characters, defined as 1 st argument, 
    and counts how many times it appears'''
    
    #The 1st argument text here represents the input in which you are looking for
    text = input("Type here the text you want: ")
    
    #The 2nd argument character represents the character you are looking for
    character = input("Type the character you want to count: ")
        
    
    
    text.count('character')
    print text.count

Answer 1

有你想要的代码，
我创建了一个带有两个参数的函数搜索：

• text 我搜索的字符串
• 字符我要数的字符串

然后我将字符的出现次数存储在字符串文本中并打印出来

def search(text,character):
    '''This function searches for one character, defined as 2nd argument, 
    in a given text / string of characters, defined as 1 st argument, 
    and counts how many times it appears'''
    
    occ = text.count(character)
    print("Occurences:",occ)

#The 1st argument text here represents the input in which you are looking for
text = input("Type here the text you want: ")

#The 2nd argument character represents the character you are looking for
character = input("Type the character you want to count: ")
search(text,character)

Answer 2

在您的代码中，您应该将 text.count(character) 保存在一个变量中，然后打印该变量。您没有看到任何内容，因为您没有打印正确的内容。 此外，您应该将变量字符放在 count 中，而不是字符串 'character'

var = text.count(character)
print var

Answer 3

根据您的规范，该函数只返回值，不打印。作为最佳实践，函数应该只做一件事。这将提高它们的可重用性。如果您还要在函数内部打印出现次数，那将限制您可以使用该函数的其他地方。

在这里我输入了一个字符串和一个字符，然后我使用我的函数找出了该字符在字符串中出现的次数：

def search(text, character):
count = 0

# for every c (stands for character) in text    
for c in text:
    if c == character:
        count += 1
        
return count

txt = input('Enter text: ')
ch  = input('Enter character: ')

print('Number of occurrances: ', search(txt, ch))

请注意，您也可以将search(txt, ch) 保存在cnt = search(txt, ch) 等变量中，以便以后使用。您也可以使用您的变量进行打印，例如print('Number of occurrances: ', cnt)。